This invention relates to a process for tenderizing meat to prepare it for cooking.
Aging of meat can be carried out by storing pieces of the meat in a refrigerated space for a time sufficient to permit natural enzymes to complete a tenderizing process. Enzymes in the meat continue to function postmortem to catalyze the hydrolysis of collagen and other proteins. The enzymes break down connective tissue so that the meat becomes tender and flavorful. After aging, the texture of the meat is more acceptable to the consuming public.
During aging, the meat is generally refrigerated at a temperature of about 34.degree. F. to suppress bacterial growth and at a relative humidity of about 80% to suppress mold growth. However at these conditions, the rate of enzymatic action is suppressed. An average of twenty-one days or more is often required to obtain satisfactory tenderizing. Substantial space in a refrigeration facility is required to store the meat for this period of time.
Increasing the temperature used in the aging process accelerates activity of the enzymes for tenderizing meat. However, bacterial activity is also increased. Slime growth, putrefaction and mold growth result in spoilage and can cause a substantial loss of usable meat. Maintaining low humidity in the refrigerated space to retard mold growth tends to desiccate and discolor meat. The desiccated and discolored parts must be trimmed. Additionally, low humidity causes shrinkage.
U.S. Pat. No. 2,713,002 to Williams proposes aging meat by storing a carcass in the presence of ultraviolet radiation. The carcass is wrapped in a combination of absorbent material with a moisture-vapor-permeable, pliable, extensile film. The meat is wrapped in the film and held under ultraviolet radiation for five, ten, fifteen or twenty days at between 30.degree. F. to 40.degree. F.; for five or ten day periods at 47.degree. F.; for two, three or five days at 60.degree. F.; or for one or two days at 70.degree. F. The covered meat is initially chilled in a cooler at a temperature of about 30.degree. to 45.degree. F. A period of twenty-four to seventy-two hours is required to bring the meat to an initial chill temperature for aging of about 30.degree. F. to 35.degree. F.
U.S. Pat. No. 3,445,240 to Bedrosian et al. discloses tenderizing meat by storage under specific controlled chilled conditions and for definite periods of time in an atmosphere containing controlled amounts of oxygen and carbon dioxide at a high humidity.
U.S. Pat. No. 3,552,297 to Williams relates to an apparatus for aging and flavoring meat at a temperature of around 65.degree. F. to 75.degree. F. The apparatus includes a germicidal lamp and a timer motor for setting the aging process for a period of one to four days. The aging process is conducted in the presence of Thamnidium, an anti-bacteria agent.
U.S. Pat. No. 3,663,233 to Keszler teaches a process of tenderizing and cooking meat products by pumping the beef with a liquid tenderizing agent. The beef is heated to a constant temperature and maintained at such temperature to allow tenderizing by the tenderizing agent. The temperature is then raised to cook the meat.
U.S. Pat. No. 3,961,090 to Weiner et al. teaches pumping an aqueous solution into a piece of uncooked beef, vacuum sealing the beef in a bag and cooking the beef "to attain a maximum internal temperature of 131.degree. to 140.degree. F."
U.S. Pat. No. 3,966,980 to McGuckian discloses a method of cooking foods in vacuum packages in a thermostatically controlled hot water bath followed by quick chilling and storage at 28.degree. F. to 32.degree. F. The bath is maintained in a range between 140.degree. F. to 212.degree. F. to cook the meat at least to a "rare" state. The cooked food is thereafter quick chilled for storage. A disclosed advantage of the process is that the meat may be enzymatically tenderized while it is being cooked.
U.S. Pat. No. 4,233,323 to Sway et al. discloses a tenderization process of exposing meat to ultraviolet rays of high intensity.
U.S. Pat. No. 4,346,650 to Zaitsu discloses a bath for sterilizing and cooking food. The process is a two-step process requiring sterilization at about 105.degree. C. (221.degree. F.) to about 140.degree. C. (284.degree. F). The bath sterilizes and cooks packaged foods.
U.S. Pat. No. 4,983,411 to Tanaka et al. relates to an apparatus used for ultraviolet sterilization and shrink film packaging food. In the packaging step, the food is sprinkled with hot water.
A process of quick aging meat by exposure to an elevated temperature is desired. However, elevated temperatures for periods required to quick age meat can cause the meat to decompose by cooking, and even normal thermostatic controls can cause non-uniform tenderization and cooking. Elevated temperatures at shorter periods of time can stimulate bacteria growth causing spoilage, and measures such as ultraviolet irradiation and chemical treatment to combat spoilage can be undesirable and expensive.